THURSDAY, Feb. 22, 2018 (HealthDay News) -- Doctors can offer patients a new version of the nasal spray flu vaccineFluMist next winter, a U.S. government advisory panel says.

Two years ago, the Advisory Committee of Immunization Practices withdrew its recommendation for FluMist after research found that it was largely ineffective.

But on Wednesday, the panel voted 12-2 to recommend FluMist as an option for the next flu season. It's the only nasal spray flu vaccine on the market and is approved for people aged 2 to 49.

FluMist maker AstraZeneca said a small study found that a new version of the nasal spray vaccine seems to be more effective than the older version, the Associated Press reported.

Two U.S. doctors said the new research appears to have swayed the panel.

"In the past, the vaccine didn't perform as it had promised to avoid influenza. The newer version is supposed to be improved; it is yet to be determined if that will be the case," said Dr. Michele Belding. She is an internal medicine and gastroenterology specialist at Northwell Health's Long Island Jewish Forest Hills Hospital in Forest Hills, N.Y.

Dr. Len Horovitz, a pulmonary specialist from Lenox Hill Hospital in New York City, concurred.

"While nasal flu vaccines were pulled from use two years ago, a new version shows efficacy that will make it an addition to the injectable vaccine armamentarium against the flu next winter," he said.

Currently, the United States is going through a particularly tough flu season, with severe cases at epidemic levels and hospitals clogged with patients battling the illness.

In 2016, the U.S. Centers for Disease Control and Prevention's advisory committee on vaccines reported that FluMist was ineffective and advised against its use.

The difference in the vaccines' effectiveness was due to their makeup: FluMist was a live but weakened influenza vaccine, while the flu shot contains a dead virus.

In 2016, the CDC committee found that the nasal spray was only 3 percent effective in preventing flu, essentially offering no protection. By comparison, the vaccine in the flu shot is 40 percent to 60 percent effective in most flu seasons, according to the CDC.

But the new, small study seems to show FluMist's effectiveness has improved.

AstraZeneca said in a statement that researchers tested the new version of FluMist on 200 U.S. kids aged 2 to 4, and found it was 23 percent effective in preventing the flu. After a second dose, those results increased to 45 percent, the company said.

However, Belding noted that those with compromised immune systems should not get this vaccine "since it has not been studied enough."

Also, a recent study found that removing the nasal spray vaccine from the market did not prompt a drop in child immunizations, at least in Oregon.

FluMist is produced by MedImmune, a subsidiary of AstraZeneca. It was licensed in 2003 and was the only non-injection flu vaccine available, the CDC said.